Fix friction for DART on Ubuntu Focal

[ctampier]

Environment

• OS Version: Ubuntu 20.04 (dockerized)
• Source or binary build? binary, ignition-fortress

Description

• Expected behavior: robot should roughly move in circles
• Actual behavior: robot moves mostly straight, occasionally turns in 90 degrees

Steps to reproduce

1. run the world found in https://github.com/ignitionrobotics/ign-gazebo/blob/ign-gazebo5/examples/worlds/skid_steer_mecanum.sdf
2. run the command: ign topic -t "/model/vehicle_blue/cmd_vel" -m ignition.msgs.Twist -p "linear: {x: 0.5}, angular: {z: 0.5}"

Output

[chapulina]

I believe this is an issue with the DART version on Ubuntu Focal. On Ubuntu Bionic we use our fork of DART, which has better friction support. Can you check what libdart version you have installed?

Related issues: gazebosim/gz-physics#49. gazebosim/gz-physics#258

[ctampier]

Thanks for the reply Louise. The version of DART in my container appears to be 6.9.2-2build4.
Unfortunately I don't know much about physics engines. Any hint on how it would be possible to overcome this issue?

[chapulina]

Any hint on how it would be possible to overcome this issue?

Some workarounds for now:

• Using Ubuntu Bionic
• Compiling our DART fork and all of Ignition from source on Focal

[scpeters]

Any hint on how it would be possible to overcome this issue?

Some workarounds for now:

• Using Ubuntu Bionic
• Compiling our DART fork and all of Ignition from source on Focal

one other workaround is using the dartsim PPA